The objective of this research is to find how the scientist or practitioner searches abstracting and indexing services. More specifically, we wish to study behavior of pathologists and pharmacists in their use of unassisted searching of National Library of Medicine databases online. Analysis of the process will show mismatches between the system and the searcher that could be remedied by change in the system or by educating the user. Traffic logs and questionnaires will be used to establish a baseline of kinds of searches performed and types of searchers who have used the system over the past five years. Changes in performance during that period will be determined, using such objective measures as number of logical operators per search to describe its complexity, and number of different basic techniques used to show the sophistication of the searcher. Number frequency of occurrence of a number of specific problems will also be analyzed. A follow-up study will have the original searcher evaluate a MEDLINE analyst's search against his own to validate the importance of specific problem areas and the end user's subjective assessment of his own searches.